Eddy, T. P., Stock, Anne L., and Wheeler, Erica F. (1971).Brit. J. industr. Med.,28, 330-341. Nutritional and environmental studies on an ocean-going oil tanker. 3. Energy balances and physique. During the voyage of the oil tanker S.S. Esso Newcastle to the Persian Gulf(July to August, 1967) the average dietary intake of the whole ship's complement was measured on eight days at different periods of the voyage. In addition, the individual intakes of six subjects (three crew and three students) were measured on three occasions over periods of three days. Estimates were also made of the energy expenditures of three members of the crew and body weight and skinfold thickness were measured.

Energy expenditure balanced energy intake in two of the crew members investigated. In the third crew subject, expenditure exceeded intake and there was a slight loss of weight. Two out of the three student subjects showed a significant gain in weight by the end of the voyage.

The average calorie intake for the ship was 15·07 megajoules (MJ) (3600 kcal) per man per day (of which 13·23 MJ (3160 kcal) were derived from non-alcoholic sources). This is the United Kingdom recommended intake for very active men. Issues on the Esso Newcastle were 18·83 MJ (4500 kcal)/man/day; the difference between provision and consumption was found to be similar to that reported for Scandinavian vessels.

Though the crew tended to be heavier than British landsmen, they did not appear to be abnormally fat. Weight was attributable to muscularity.

El Ghawabi, S. H., Mansour, M. B., Youssef, F. L., El Ghawabi, M. H., and Abd El Latif, M. M. (1971).Brit. J. industr. Med.,28, 323-329. Decompression sickness in caisson workers. An investigation of 55 bridge construction workers is reported. The overall bends rate was 0·97%. (The term `bends' as used in this study is defined in the paper.) Chokes were encountered in 67·27% of workers. A clinical, haematological, and radiological study was performed.

Definite bony changes were found in 43·6% of all workers; 91·6% of these had lesions around the elbow. The presence of dense areas in the neck of the scapula is reported in two cases for the first time. The relatively high haematocrit value is thought to play a part in the pathogenesis of bone infarction through its relation with blood viscosity.

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Smiley, J. A. (1971).Brit. J. industr. Med.,28, 315-322. Some aspects of the early evolution of the Appointed Factory Doctor Service. The appointment of certifying surgeons marks the beginning of the recognition by the State of its responsibility for the supervision of the health and welfare of young people in industry. The importance of the rôle played by Leonard Horner, one of the first four inspectors of factories, is discussed. Some of the problems and vicissitudes of the service in the 19th century are outlined and it is suggested that the system is inappropriate to the needs of the present. Legislation which would integrate all the agencies which are concerned with the well-being of young people, including the Appointed Factory Doctor Service, should be actively considered.

Hearn, C. E. D., and Keir, W. (1971).Brit. J. industr. Med.,28, 399-403. Nail damage in spray operators exposed to paraquat. Nail damage in 55 persons due to contamination by diluted paraquat in a group of 296 spray operators employed on a sugar estate in Trinidad is described.

The commonest lesion seen was transverse white bands of discoloration, but loss of nail surface, transverse ridging, gross deformity of the nail plate, and loss of nails occurred. The index, middle, and ring fingers of the right hand were predominantly affected and this could be ascribed to leakage from the knapsack sprayer.

It is emphasized that, although the degree of contamination was unusually gross, it is nonetheless important to recognize that the diluted material can cause nail damage. Simple hygienic precautions and proper maintenance of spraying equipment can prevent its occurrence. Periodic medical examinations are recommended even for workers exposed only to diluted paraquat.

The distribution of the nail lesions confirms that they are the result of a local action. Following cessation of further exposure subsequent nail growth is normal.

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Cernik, A. A., and Sayers, M. H. P. (1971).Brit. J. industr. Med.,28, 392-398. Determination of lead in capillary blood using a paper punched disc atomic absorption technique. Application to the supervision of lead workers. The presence of lead in blood is the most incontrovertible evidence of absorption but hitherto the need for venepuncture has limited its determination in the supervision of industrial workers. Micro-methods using atomic absorption spectrophotometry (AAS) have, however, made possible the development of a sufficiently reliable test using a drop of blood obtainable by ear prick for use in the field for screening purposes.

A micro-sampling method by AAS is compared with a routine polarographic procedure (POL) using venous blood (corr. coeff. = 0·990). The pipetting of microlitres of blood can be eliminated by spotting the blood onto filter paper, allowing it to dry in air, and then using a punched-out standard disc of dried blood for analysis instead. Correlation of this method (PD) with the micro-sampling technique (AAS) is good (r=0·981).

The PD method using capillary blood also correlates acceptably with the micromethod using venous blood (r = 0·913). A pilot field study using capillary blood estimated by the PD technique showed that with this method blood can be collected by ear prick in factories for monitoring workers in the lead industry, thus eliminating the need for routine venepuncture.

Ogata, M., Yoshiko, T., and Tomokuni, K. (1971).Brit. J. industr. Med.,28, 386-391. Excretion of organic chlorine compounds in the urine of persons exposed to vapours of trichloroethylene and tetrachloroethylene. Male volunteers were exposed to 170 p.p.m. of trichloroethylene vapour either for 3 hours or for 7 hours with one break of 1 hour; or to 87 p.p.m. of tetrachloroethylene vapour for 3 hours. Urine was collected frequently up to 100 hours after the start of exposure, and was analysed for trichloroethanol and trichloroacetic acid. After trichloroethylene exposure, trichloroethanol was excreted most rapidly shortly after exposure ceased, and trichloroacetic acid most rapidly 42 to 69 hours after exposure ceased. Total recoveries of trichloroethylene inhaled, up to 100 hours, were: trichloroethanol, after 3 hours' exposure, 53·1%; after 7 hours' exposure, 44%; trichloroacetic acid, similarly: 21·9% and 18·1%. The effects of exposure on blood pressure, pulse rate, flicker value, and reaction time were measured. The diastolic blood pressure was decreased significantly after 3 hours' exposure to 170 p.p.m. trichloroethylene. After tetrachloroethylene exposure, in 67 hours trichloroacetic acid was excreted to 1·8% tetrachloroethylene retained and an unknown chloride equivalent to 1·0%.

Urine samples from 10 workers in an automobile parts factory were analysed for trichloroethanol and trichloroacetic acid. Trichloroethanol concentrations in the urine taken after work were higher than in the urine taken before work while for trichloroacetic acid the concentrations were reversed, due to the difference in the time course of excretion. The urinary levels of trichloroethanol, trichloroacetic acid, and total trichloro compounds were almost proportional to the environmental concentration of trichloroethylene.

Ogata, M., Takatsuka, Y., and Tomokuni, K. (1971).Brit. J. industr. Med.,28, 382-385. Excretion of hippuric acid and m- or p-methylhippuric acid in the urine of persons exposed to vapours of toluene and m- or p-xylene in an exposure chamber and in workshops, with specific reference to repeated exposures. Four male volunteers were exposed to 200 p.p.m. of toluene for five one-hour periods separated by one-hour intervals. The excretion curve of hippuric acid showed multi-peaks, and almost concided with a theoretical curve previously described. The fraction of the toluene absorbed which was accounted for as hippuric acid was only slightly lower than after a single exposure.

In a paint spraying shop exposure was measured both from the concentrations of toluene in the air by a Kitagawa detector and from the exceretion of urinary hippuric acid. The results were in general agreement, with a correlation coefficient of 0·67.

Urinary hippuric acid and methylhippuric acid were determined on urines from two workers in a shipbuilding yard who used paint thinned with toluene and xylene. The concentrations of the acids varied from day to day depending on the kind and the duration of work. From the concentrations found the mean concentrations to which the workers were exposed were calculated as a fraction of the maximum allowable concentration (M.A.C.). One worker was, on this evidence, exposed to more than the combined M.A.C. on three days out of six.

Hänninen, H. (1971).Brit. J. industr. Med.,28, 374-381. Psychological picture of manifest and latent carbon disulphide poisoning. A battery of psychological tests was administered to 50 viscose workers with carbon disulphide (CS2) poisoning, 50 viscose workers exposed to CS2 without known poisoning, and 50 workers not exposed to CS2. There were large and statistically significant differences between the group means of the poisoned and the unexposed group in most performances involving speed, vigilance, manual dexterity, and intelligence. The exposed group also showed impairment, but the changes were less severe. CS2 thus apparently affects the working capacity and sociability of exposed workers earlier than can be diagnosed by purely medical means.

The differences between the groups were further studied by discriminant function analysis. The poisoned group could be reliably discriminated from the unexposed group. Of the unexposed and poisoned subjects, 91% were correctly classified in the proper group. The exposed workers could not be discriminated from the poisoned subjects with the same reliability owing to the effects of latent CS2 poisoning in the former group.

Analysis of the discriminant functions further suggests that the syndromes of latent and manifest CS2 poisoning differ not only in intensity but also in quality. Clinically manifested poisoning is characterized by lowered vigilance, diminished intellectual activity, diminished rational control, retarded speed, and motor disturbances, whereas traits indicative of depressive mood, slight motor disturbances, and intellectual impairment are characteristic of latent poisoning. This syndrome is probably much more common than was hitherto believed.

Jones, R., Baetjer, A. M., and Reid, L. (1971).Brit. J. industr. Med.,28, 369-373. Effect of extremes of temperature and humidity on the goblet cell count in the rat airway epithelium. To investigate the effect of environmental temperature and humidity on the goblet cells in the rat airway epithelium, eight animals were exposed for four to five weeks to each of the following conditions: normal; hot-moist or tropical; hot-dry or desert; and cold. The animals in the three groups exposed to abnormal atmospheric conditions failed to gain weight as fast as those in the control group. No increase in the number or area of goblet cells was found in any group, although with irritants previously tested, such as tobacco smoke, a marked increase has been found in this time. It would seem that climatic effects are much less important than irritation in the production of hypertrophy and hyperplasia of mucus-secreting cells, the hallmark of chronic bronchitis.

Valić, F., and Žuškin, E. (1971).Brit. J. industr. Med.,28, 364-368. A comparative study of respiratory function in female non-smoking cotton and jute workers. To compare the effect of cotton and jute dust, respiratory symptoms were studied and respiratory function measured in 60 cotton and 91 jute non-smoking female workers of similar age distribution, similar length of exposure to dust, and exposed to similar respirable airborne dust concentrations. Cotton workers had a significantly higher prevalence of byssinosis, of persistent cough, and of dyspnoea (P < 0·01) than jute workers. Among cotton workers 28·3% were found to have characteristic symptoms of byssinosis, whereas none was found among jute workers.

Exposure to cotton but also to jute dust caused significant reductions of FEV1·0, FVC, and PEF (P < 0·01) over the first working shift in the week. Functional grading of jute and cotton dust effects has shown that about 30% of cotton workers had functional grades F1 and F2, while only 13% of jute workers were found in the same grades (F1). It is concluded that cotton dust may be considered more active than jute though the latter cannot be considered inactive.

Walker, D. D., Archibald, R. M., and Attfield, M. D. (1971).Brit. J. industr. Med.,28, 358-363. Bronchitis in men employed in the coke industry. An epidemiological survey to determine the prevalence of bronchitis in men employed at two of the National Coal Board's coking plants is described. Eight hundred and eighty-one men (91%) of the total working population were examined.

A strong association was found between bronchitis prevalence and cigarette smoking (P < 0·001). In addition, men who smoked and who were exposed to high temperatures, dust, and fumes in the environment of the coke-ovens had more bronchitis than men who worked elsewhere in the cokeworks (P < 0·02).

Both the presence of bronchitis and employment in the environment of the coke-ovens had significant and independent effects on ventilatory capacity. The combination of cigarette smoking and previous employment in a dusty industry also had a significant effect on ventilatory capacity.

The investigation suggests that cigarette smoking, and the combination of smoking and pollution from the coke-ovens and previous occupation, appear to be important factors in the aetiology of bronchitis and reduced ventilatory capacity in men employed in the coke manufacturing industry.

Okada, A., Yamashita, T., Nagano, C., Ikeda, T., Yachi, A., and Shibata, S. (1971).Brit. J. industr. Med.,28, 353-357. Studies on the diagnosis and pathogenesis of Raynaud's phenomenon of occupational origin. Experiments were designed to investigate tests for the diagnosis of Raynaud's phenomenon of occupational origin between attacks and to investigate the pathogenesis, particularly with reference to factors in the patient. The fingertip blood flow was low not only in subjects with Raynaud's phenomenon (positive group) but also in other users of vibrating tools who did not have Raynaud's phenomenon (negative group). This criterion combined with urinary vanillyl mandelic acid and haptoglobin was examined by analysis of discriminant function. The probability of false discrimination was 3%. Histamine iontophoresis performed after noradrenalin iontophoresis with subsequent comparison of pulse wave amplitudes is useful for identification of the positive group. Haptoglobin was significantly increased and the subjects in whom IgM was increased formed a high proportion of the positive group.

Eddy, T. P., Wheeler, Erica F., and Stock, Anne L. (1971).Brit. J. industr. Med.,28, 342-352. Nutritional and environmental studies on an ocean-going oil tanker. 4. The diet of seamen. Previous reports by Collins and his colleagues (1971a, b) and Eddy, Stock, and Wheeler (1971) have described energy and nutrient balances measured during a voyage of the oil tanker S.S. Esso Newcastle to the Persian Gulf in July and August 1967. This study of the diet of seamen during the voyage describes inter-relationships of the energy-yielding constituents of the diet, particularly the relationship of alcohol to other constituents, and vitamin intakes.

For the whole ship's crew the percentages of energy derived from the main constituents were from protein 12%, fat 35%, carbohydrate 40%, and alcohol 13%.

The intakes of six subjects studied in detail showed relatively little variation in protein, 13·9 ± 0·4 Joules%; but greater variation in fat (33·0 ± 1·6%), carbohydrate (42·7 ± 1·4%), and alcohol (10·4 ± 1·3%). There were high negative correlations, r=-0·75, between energy percentages derived from alcohol and those derived from protein and fat respectively.

Flour purchased for the ship in a foreign port was deficient in thiamine and niacin. There was a negative correlation between energy and thiamine intake, and with unfortified white flour thiamine intake would fall below the recommended allowance at intakes above 14·5 MJ (3500 kcal). The unwitting substitution of unfortified flours in place of fortified British flour is a potential cause of deficiency.

The estimated intake of riboflavine decreased when fresh milk supplies were exhausted following the 10th day out, and would have fallen below the recommended intake of 0·5 mg/1000 kcal (4·186 MJ) but for the consumption of beer.

The intake of ascorbic acid was not affected by the duration of the voyage. It averaged 70mg/man/day and was derived chiefly from citrus fruits and potatoes.

The Statutory Scale of Provisions issued under the Merchant Shipping Act. 1906, is out of date and a new scale should be drawn up.

Fukuda, K. (1971).Brit. J. industr. Med.,28, 308-311. Metallic mercury induced tremor in rabbits and mercury content of the central nervous system. Tremor induced by metallic mercury was experimentally produced in rabbits by intermittent exposure to mercury vapour (average concentration of 4·0 mg/m3 for 6 hr/day on 4 days/week for 13 successive weeks). Two of six male rabbits exposed developed fine tremor and clonus in the fore- and hind-legs after 13 weeks' exposure. Electromyographic records showed typical grouped voltages accompanying the clonus (amplitude 0·3 to 1·0 mV, duration 20 to 30 ms, frequency 14 to 15 per second).

Activation analysis of the central nervous system showed mercury levels ranging from 0·8 to 3·9 μg/g wet tissue. The concentration in the cerebellum, the tegmentum, and the thalamus was significantly higher than in the remaining structures. The relationship between the tremor and the mercury content of the central nervous system is discussed and a positive causal relationship is suggested.